1. Field of the Invention
This invention concerns a method for forming crystalline semiconductor layers and a method for fabricating thin film transistors, active matrix liquid crystal devices and solar cells that employ these crystalline semiconductor layers.
2. Description of the Related Art
Polycrystalline silicon and other semiconductor films are used widely in thin film transistors (xe2x80x9cTFTxe2x80x9d in the specifications of this application) and solar cells. The performance of these semiconductor devices is strongly dependent on the quality of the semiconductor layer, which wholly constitutes the active portion of the semiconductor device. Needless to say, if a high-quality semiconductor layer can be created, a semiconductor device with correspondingly high performance can be produced. For example, in a polycrystalline silicon thin film transistor (poly-Si TFT) used in such products as liquid crystal display devices, the higher the quality of the polycrystalline silicon (poly-Si) layer, the faster the switching speed of the TFT. Likewise, given roughly similar light absorption efficiency, a solar cell having a semiconductor layer with a higher degree of crystallinity will convert energy more efficiently. There is, therefore, strong demand in many industries for high quality crystalline semiconductor layers.
However, the formation of this kind of high quality semiconductor layer is generally difficult to achieve and, moreover, is subject to important limitations. In the field of TFTs, polycrystalline silicon layers having relatively high mobility are formed by fabricating transistors by means of a high temperature process where maximum process temperatures reach about 1000xc2x0 C. Because of this, semiconductor films and semiconductor devices can be formed only on those substrates having thermal resistance properties that enable them to withstand high temperature processing. For this reason, all of today""s poly-Si TFTs are formed on expensive, small quartz glass substrates. For the same reason, amorphous silicon (a-Si) is normally used for solar cells.
Against this backdrop, various research has been conducted on methods of forming high quality semiconductor layers at the lowest temperature possible. Solid-phase crystallization is known as the first such method. In this process, an a-Si film is formed on the substrate and then subjected to annealing at a temperature of approximately 600xc2x0 C. for a minimum of 10 hours, thereby converting said a-Si film to a poly-Si layer. Laser crystallization is acknowledged to be the second process. In this method, an a-Si film is first deposited and then exposed to laser irradiation, thereby promoting crystallization of the silicon film.
However, the first of the conventional technologies (solid phase crystallization) requires annealing over a long period of timexe2x80x94more than 10 hoursxe2x80x94and thus suffers from extremely poor throughput. Moreover, in this process thermal deformation of the substrate arising from prolonged heating of the entire substrate has become a major problem, meaning essentially that inexpensive, large glass substrates cannot be used. The problem with the second of the conventional technologies (laser crystallization) is that crystallization does not progress if the laser irradiation energy is too low, while high energy will damage the semiconductor film. Hence, satisfactory, high quality crystalline films cannot be produced under either of the irradiation conditions. Moreover, extensive nonuniformity in crystallinity is known to occur with each laser irradiation. The result is that even if these semiconductor films are applied in TFTs, for example, good transistor characteristics cannot be obtained.
Accordingly, a third method is being studied, which combines the second of the conventional technologies (laser crystallization) with a variation of the first (furnace annealing). This is a semiconductor film annealing process that is performed after the semiconductor film is crystallized by a laser. In this process the annealing temperature is lower (450xc2x0 C. to 550xc2x0 C.) than that used in solid-phase crystallization and the annealing time is shorter (one to five hours). Nevertheless, this process, too, has essentially the same problems as those of the first method. That is, even if the annealing temperature were kept to about 450xc2x0 C., throughput would be poor because annealing would be required for at least several hours and, moreover, thermal distortion of the substrate could not be ignored.
Therefore, the aim of the present invention is to solve the aforementioned problems. The objective is to provide a method of forming high quality crystalline semiconductor layers with high throughput without subjecting the substrate to excessive thermal stress and, using this method, to provide a method of producing high performance thin film transistors and solar cells.
To solve the aforementioned problems in a method for forming crystalline semiconductor layers on a substrate, this invention is characterized by a semiconductor film deposition process in which a semiconductor film is deposited on a substrate, a first annealing process in which said semiconductor film is crystallized by repeatedly performing a process that melt crystallizes a portion of said semiconductor film, and a second annealing process in which rapid thermal annealing is performed on said crystallized semiconductor film. Here, the annealing temperature in the aforesaid second annealing process is expressed by the absolute temperature T [K] and, when the annealing time is t [seconds], annealing temperature T and annealing time t are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
(xcex5=3.01[eV], k=8.617xc3x9710xe2x88x925[eV/K]: Boltzmann constant) 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT). 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec ] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
They are also characterized by the fact that when the two equations directly above are satisfied, the substrate is glass and annealing temperature T is below the strain point of said glass substrate. In addition, this invention is characterized by the fact that annealing time t is 300 seconds or less, and is also characterized by the fact that the annealing time t is 180 seconds or less.
In a method of forming crystalline semiconductor layers on a substrate, this invention is also characterized by a semiconductor film deposition process in which a semiconductor film is deposited on a substrate, a first annealing process in which said semiconductor film is repeatedly exposed to local laser irradiation, and a second annealing process in which rapid thermal annealing is performed on said laser-irradiated semiconductor film. Here, the annealing temperature in the aforementioned second annealing process is expressed by the absolute temperature T [K] and when the annealing time is t [seconds], annealing temperature T and annealing time t are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
(xcex5=3.01[eV], k=8.617xc3x9710xe2x88x925[eV/K]: Boltzmann constant) 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT). 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
They are also characterized by the fact that when the two equations directly above are satisfied, the substrate is glass, and annealing temperature T is below the strain point of said glass substrate. In addition, this invention is characterized by the fact that the annealing time t is 300 seconds or less, and is also characterized by the fact that the annealing time t is 180 seconds or less.
In addition, in a method of forming crystalline semiconductor layers on a substrate, this invention is characterized by a semiconductor film deposition process in which a semiconductor film is deposited on a substrate, a first annealing process in which said semiconductor film is repeatedly exposed to local high energy optical irradiation, and a second annealing process in which rapid thermal annealing is performed on said high energy optically irradiated semiconductor film. Here, the annealing temperature in the aforementioned second annealing process is expressed by the absolute temperature T [K] and when the annealing time is t [seconds], annealing temperature T and annealing time t are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(31 xcex5/kT) 
(xcex5=3.01[eV], k=8.617xc3x9710xe2x88x925[eV/K]: Boltzmann constant). 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(31 xcex5/kT) 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
They are also characterized by the fact that when the two equations directly above are satisfied, the substrate is glass, and annealing temperature T is below the strain point of said glass substrate. In addition, this invention is characterized by the fact that the annealing time t is 300 seconds or less, and is also characterized by the fact that the annealing time t is 180 seconds or less.
In a method of fabricating thin film transistors using a semiconductor film formed on a substrate, this invention is also characterized by having at a minimum a semiconductor film deposition process in which a semiconductor film is deposited on a substrate, a first annealing process in which said semiconductor film is crystallized by repeatedly performing a process that melt crystallizes a portion of said semiconductor film, and a second annealing process in which rapid thermal annealing is performed on said crystallized semiconductor film. Here, the annealing temperature in the aforementioned second annealing process is expressed by the absolute temperature T [K] and, when the annealing time is t [seconds], annealing temperature T and annealing time t are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
(xcex5=3.01[eV], k=8.617xc3x9710xe2x88x925[eV/K]: Boltzmann constant). 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec], 
They are also characterized by the fact that when the two equations directly above are satisfied, the substrate is glass, and thermal annealing temperature T is below the strain point of said glass substrate. In addition, this invention is characterized by the fact that the annealing time t is 300 seconds or less, and is also characterized by the fact that the annealing time t is 180 seconds or less.
In a method of fabricating thin film transistors using a semiconductor film formed on a substrate, this invention is also characterized by having at a minimum a semiconductor film deposition process in which a semiconductor film is deposited on a substrate, a first annealing process in which said semiconductor film is repeatedly exposed to local laser irradiation, and a second annealing process in which rapid thermal annealing is performed on said laser irradiated semiconductor film. Here, the annealing temperature in the aforementioned second annealing process is expressed by the absolute temperature T [K] and when the annealing time is t [seconds], annealing temperature T and annealing time t are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
(xcex5=3.01[eV], k=8.617xc3x9710xe2x88x925[eV/K]: Boltzmann constant). 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT). 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
They are also characterized by the fact that when the two equations directly above are satisfied, the substrate is glass, and thermal annealing temperature T is below the strain point of said glass substrate. In addition, this invention is characterized by the fact that the annealing time t is 300 seconds or less, and is also characterized by the fact that the annealing time t is 180 seconds or less.
In a method of fabricating thin film transistors using a semiconductor film formed on a substrate, this invention is also characterized by having at a minimum a semiconductor film deposition process in which a semiconductor film is deposited on a substrate, a first annealing process in which said semiconductor film is repeatedly exposed to local high energy optical irradiation, and a second annealing process in which rapid thermal annealing is performed on said high energy optically irradiated semiconductor film. Here, the annealing temperature in the aforementioned second annealing process is expressed by the absolute temperature T [K] and when the annealing time is t [seconds], annealing temperature T and annealing time t are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
(xcex5=3.01[eV], k=8.617xc3x9710xe2x88x925[eV/K]: Boltzmann constant). 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT). 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
They are also characterized by the fact that when the two equations directly above are satisfied, the substrate is glass, and thermal annealing temperature T is below the strain point of said glass substrate. In addition, this invention is characterized by the fact that the annealing time t is 300 seconds or less, and is also characterized by the fact that the annealing time t is 180 seconds or less.
In a method of fabricating solar cells using a semiconductor film formed on a substrate, this invention is also characterized by having at a minimum a semiconductor film deposition process in which a semiconductor film is deposited on a substrate, a first annealing process in which said semiconductor film is crystallized by repeatedly performing a process that melt crystallizes a portion of the said semiconductor film, and a second annealing process in which rapid thermal annealing is performed on said crystallized semiconductor film. Here, the annealing temperature in the aforementioned second annealing process is expressed by the absolute temperature T [K] and when the annealing time is t [seconds], annealing temperature T and annealing time t are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
(xcex5=3.01[eV], k=8.617xc3x9710xe2x88x925[eV/K]: Boltzmann constant). 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT). 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
They are also characterized by the fact that when the two equations directly above are satisfied, the substrate is glass, and thermal annealing temperature T is below the strain point of said glass substrate. In addition, this invention is characterized by the fact that the annealing time t is 300 seconds or less, and is also characterized by the fact that the annealing time t is 180 seconds or less.
In a method of fabricating solar cells using a semiconductor film formed on a substrate, this invention is also characterized by having at a minimum a semiconductor film deposition process in which a semiconductor film is deposited on a substrate, a first annealing process in which said semiconductor film is repeatedly exposed to local laser irradiation, and a second annealing process in which rapid thermal annealing is performed on said laser irradiated semiconductor film. Here, the annealing temperature in the aforementioned second annealing process is expressed by the absolute temperature T [K] and when the annealing time is t [seconds], annealing temperature T and annealing time t are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
(xcex5=3.01[eV], k=8.617xc3x9710xe2x88x925[eV/K]: Boltzmann constant). 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT). 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
They are also characterized by the fact that when the two equations directly above are satisfied, the substrate is glass, and thermal annealing temperature T is below the strain point of said glass substrate. In addition, this invention is characterized by the fact that the annealing time t is 300 seconds or less, and is also characterized by the fact that the annealing time t is 180 seconds or less.
In a method of fabricating solar cells using a semiconductor film formed on a substrate, this invention is also characterized by having at a minimum a semiconductor film deposition process in which a semiconductor film is deposited on a substrate, a first annealing process in which said semiconductor film is repeatedly exposed to local high energy optical irradiation, and a second annealing process in which rapid thermal annealing is performed on said high energy optically irradiated semiconductor film. Here, the annealing temperature in the aforementioned second annealing process is expressed by the absolute temperature T [K] and when the annealing time is t [seconds], annealing temperature T and annealing time t are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
(xcex5=3.01[eV], k=8.617xc3x9710xe2x88x925[eV/K]: Boltzmann constant). 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT). 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
They are also characterized by the fact that when the two equations directly above are satisfied, the substrate is glass, and thermal annealing temperature T is below the strain point of said glass substrate. In addition, this invention is characterized by the fact that the annealing time t is 300 seconds or less, and is also characterized by the fact that the annealing time t is 180 seconds or less.
In a method of fabricating solar cells using a semiconductor film formed on a substrate, this invention is also characterized by having at a minimum a process in which a first conductive impurity diffusion source is formed on a substrate, a semiconductor film deposition process in which a semiconductor film is deposited on said first conductive impurity diffusion source, a process in which a second conductive impurity diffusion source is formed on the surface of said semiconductor film, a first annealing process in which said semiconductor film is repeatedly exposed to local laser irradiation, and a second annealing process in which rapid thermal annealing is performed on said laser irradiated semiconductor film. Here, the annealing temperature in the aforementioned second annealing process is expressed by the absolute temperature T [K] and when the annealing time is t [seconds], annealing temperature T and annealing time t are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
(xcex5=3.01[eV], k=8.617xc3x9710xe2x88x925[eV/K]: Boltzmann constant). 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
In a method of fabricating solar cells using a semiconductor film formed on a substrate, this invention is characterized by having at a minimum a semiconductor film deposition process in which a semiconductor film is deposited, a first annealing process in which said semiconductor film is repeatedly exposed to local laser irradiation, a process in which a second conductive impurity diffusion source is formed on the surface of said laser irradiated semiconductor film, and a second annealing process in which rapid thermal annealing is performed on a semiconductor film on which said second conductive impurity diffusion source is formed. Here, the semiconductor film that is deposited in the aforesaid semiconductor film deposition process is further characterized by being a layered structure comprised of a first conductive semiconductor film and an essentially intrinsic semiconductor film. Here, the annealing temperature in the aforementioned second annealing process is expressed by the absolute temperature T [K] and when the annealing time is t [seconds], annealing temperature T and annealing time t are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
(xcex5=3.01[eV], k=8.617xc3x9710xe2x88x925[eV/K]: Boltzmann constant). 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Further, in a method of fabricating solar cells using a semiconductor film formed on a substrate, this invention is also characterized by having at a minimum a process in which a first conductive impurity diffusion source is formed on a substrate, a semiconductor film deposition process in which a semiconductor film is deposited on said first conductive impurity diffusion source, a first annealing process in which said semiconductor film is repeatedly exposed to local laser irradiation, a process in which a second conductive impurity diffusion source is formed on the surface of said laser irradiated semiconductor film and a second annealing process in which rapid thermal annealing is performed on a semiconductor film formed by said second conductive impurity diffusion source. Here, the annealing temperature in the aforementioned second annealing process is expressed by the absolute temperature T [K] and when the annealing time is t [seconds], annealing temperature T and annealing time t are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
(xcex5=3.01[eV], k=8.617xc3x9710xe2x88x925[eV/K]: Boltzmann constant). 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Further, in a method of fabricating solar cells using a semiconductor film formed on a substrate, this invention is also characterized by having at a minimum a semiconductor film deposition process in which a semiconductor film is deposited, a first annealing process in which said semiconductor film is repeatedly exposed to local laser irradiation, a process in which a second conductive semiconductor film is deposited on the surface of said laser irradiated semiconductor film, and a second annealing process in which rapid thermal annealing is performed on a semiconductor film on which said second conductive semiconductor film is deposited. Here, the semiconductor film that is deposited in the aforesaid semiconductor film deposition process is further characterized by being a layered structure comprised of a first conductive semiconductor film and an essentially intrinsic semiconductor film. Here, the annealing temperature in the aforementioned second annealing process is expressed by the absolute temperature T [K] and when the annealing time is t [seconds], annealing temperature T and annealing time t are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
(xcex5=3.01[eV], k=8.617xc3x9710xe2x88x925[eV/K]: Boltzmann constant). 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT). 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Further, in a method of fabricating solar cells using a semiconductor film formed on a substrate, this invention is also characterized by having at a minimum a process in which a first conductive impurity diffusion source is formed on a substrate, a semiconductor deposition process in which a semiconductor film is deposited on said first conductive impurity diffusion source, a first annealing process in which said semiconductor film is repeatedly exposed to local laser irradiation, a process in which a second conductive semiconductor film is deposited on the surface of said laser irradiated semiconductor film, and a second annealing process in which rapid thermal annealing is performed on the semiconductor film formed by said second conductive semiconductor film. Here, the annealing temperature in the aforementioned second annealing process is expressed by the absolute temperature T [K] and when the annealing time is t [seconds], annealing temperature T and annealing time t are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) 
(=3.01 [eV], k=8.617xc3x9710xe2x88x925[eV/K]: Boltzmann constant). 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT). 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 4.63xc3x9710xe2x88x9214[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
1.72xc3x9710xe2x88x9221[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Or, they are characterized by the fact that the following relationship is satisfied:
5xc3x9710xe2x88x9218[sec] less than txc2x7exp(xe2x88x92xcex5/kT) less than 1.09xc3x9710xe2x88x9215[sec]. 
Further, in an active matrix liquid crystal device having thin film transistors, this invention is characterized by a substrate manufactured by means of the thin film transistor fabrication method described above.
The fundamental principles and scheme of the present invention are described in detail hereafter, with reference to the drawings.